I used to play uno flip a lot and here are some ideas I made for the blank cards maybe y want to use them and I made my own cards too  

UNO IDEAS

1. Copycat- literally the last card before this one.

2. uNOOOOOO!- first person to get to one card remaining has to pick up 5.

3. Steal Turn- steal a selected players from their turn, now when it’s meant to be them it’s YOU (one time only unless copycat is used making it 2)

4. No More Change- everyone puts their wild cards in the middle of the deck.

5. Suicide Bomber- the other plays draw 5 cards while the user of this card draws 2.

6. NUH UH- if someone tries do to an effect card that is undoable (isnt undoable is like blocks or 2 player reverses, bc u can’t place if it’s not your turn yet) then u can just place the nuh uh card after and the effect will be sent towards the other player (eg pick up cards) or undoed (eg wild cards)

7. Value Matters- everyone shows their highest number card, the person with the lowest number picks up 5. If a tie, just play on.

8. Factory Reset- everyone is back to 7 new cards from the deck, their old cards being put back in the deck.

9. Flip The Deck- only the DECK is being flipped here.

10. I didn’t agree to this!- give a selected person two of your cards

11. Half n’ Half-  everyone gives half their cards to the next person

12. 10,10, Keir’s Den- if you get or have over 10 cards from now to the rest of the game your out.

13. Weakened Wild- wild card that only changes to red and blue, orange and pink.

UNO blank card ideas